Brake



June 17, 1941. H, H, KERR 2,245,682

7 BRAKE Filed My 9, 1938 5 Sheets-Sheet 1 Fae. l

INVENTOR- HBNRY H; Kenn 7 607 I ATTORNEY.

H. H. KERR Ju ne 17,1941.

BRAKE Filed May 9, 1938 5 Sheets-Sheet 2 Fee. 4

K rNwgroR.

HEN Y H BY ATTORNEY.

KERR I 2;245, 682

BRAKE Filed May 9, 1938 l 5 Sheets-Sheet 3 INV EN TOR.

Hemzv H. Kemp,

BY dQww- ATTORNEY.

Iune 17, 1941;

" INVENTOR HENRY H; KtRR/ BY ATTORNEY.

5 sneets sheet 4 June 17, 1941. H, H, KER 2,245,682

' BRAKE Filed May 9, 1938 5 Sheets-Sheet 5 FIG. 9

V INVENTOR. BY HENRY KERR.

ATTORNEY.

Patented June 17, 1941' UNITED STATES PATENT OFFICE BRAKE Henry H. Kerr, South Bend, Incl, aslignor to Bendix Products Corporation, Ind., a corporation of Indiana Application May 9, 1938, Serial No. 206,203

South Bend,

1: mm. (Cl. 188-152) This invention relates to brakes and more particularly to fluid brake systems in which a fluid is used to force the brake shoes or friction materials against a brake drum to obtain braking power.

Heretofore, fluid brake systems have been proposed and used in which safety devices have been incorporated. These systems, however,- do not insure the operation of all brakes, 'but insure means for each individual brake'and provide that even though one actuator fails, the brake may still he operable by means of the-other actuator or actuators. I

Cine of the objects of this invention is to provide a fluid brake system whereby each brake is applied by two or more separate actuating means.

system on anairplan'e constructed according to my invention;

Figure 3 is a diagrammatic view of a braking system difl'erent from that shown in Figure 2 but still embodying the idea of my invention;

Figure 4 is a detailed view in section of. a safety valve for a hydraulic brake system which may be used with my invention as shown in Figure 3;

' Figure 5 is a detailed view in section of one of the control valves shown in the braking systemsv illustrated in Figures 2 and 3 which may be usedwith my valve;

Figure 6 is a cross-sectional view of an alternate form of tube type brake arranged to embody the idea of my invention;

Figure 7 is a cross-sectional view of still another form of tube type brake also arranged to embody the ideaof my invention;

Figure 8 is a vertical section of another form of tube type brake arranged to embody the idea of my invention; and

Figure 9 is a diagrammatic view of a braking system of an airplane constructed according to my invention utilizing a pressure control system similar to that shown in Figure 2 and utilizing brakes of the form shown in Figure 8;

Another object of the invention is to provide a fluid brake system with two or more separate mtuators for each individual brake, one or more of which will still operate the brake even though a the other actuators fail. I

one of the features of the invention is a fluid twinplex brake which is operable as a twinplex brake under all ordinary conditions, but if one of the actuators should fail, the brake becomes operable as a double anchor non-servo brake.

A further feature of the invention is a fluid brake system that has two or more expansible tubes filled with fluid, said tubes being used to iorce the brake lining against the brake drum as a controlled fluid pressure is used to expand them. Individual controlling means for each tube or group of tubes is used. The system is so-.constructed that it one tube or group of tubes fail. the other tube or group of tubes is still able to operate the brake.

Further objects and features of the invention will be apparent after a study of the following drawings of which:

Figure 1 is .a side view of a twinplex ,brake which may be used with my invention;

Figure 2 is a diagrammatic view of a braking Referring in detail to the drawings, Figure 1 shows a hydraulically actuated twinplex b'rake. with aspider I provided with holes 2 to mount the brake to the axle of a vehicle or aircraft. Brake shoes 3' and 4 are anchored on caps ill,

ii, I! and ii that fit over the ends of hydraulic wheel cylinders 5 (shown in section) and 6. The hydraulic wheel cylinders 5 and 6 are each pro-.

-vided with two pistons l4 and I5, two .rubber cups l1 and "and end caps'such as I0 and II, and I2 and 13. At each end of the shoes 3 and 4 are adjustments such as 20 and 22, and I9 and 2| respectively; Brake linings 1 and 8 are also attached to shoes 3 and 4 respectively. -The adjustments are latched by springs 23 at all times except when manually adjusted. The brake is normally held in the off position means of springs 24 and 25.

In operation when fluid is forced into the fluid wheel cylinders 5 and 6, the pistons in both specification and claims, and of the attached cylinders move outwards together with the caps N, II, I! and i3 and the adjustments |9, 20, 2| and 22 The brake shoes 3 and4, carrying the brake linings 1 and 8 respectively, are then forced outward against the spring pressure 015 the springs 24 and 25 and into contact with the brake drum 8. If the rotation of the drum 9 is clockwise, the shoe 3 will anchor on the cap and the shoe 4 will anchor on the cap I0. If'the rotation, however,' is in the opposite direction, the shoe 4 will anchor on the cap I2 and the shoe 3 will anchor on the cap II.

In Figure 2, a fluid brake system for an air- I plane embodying the idea. of the invention is shown. The brakes 23 and 30 (one of which is shown in detail in Figure l) are controlled by means of two foot pedals 3| and 32 which may operate control valves such as 33, 34, 35 and 30 through connecting links 31, 33, 33 and 40 respectively. Fluid under pressure enters control valves 33, 34, 35 and 30 from a compressor 4! having an outlet 5i into the inlets 41, 40, 49 and '50 of the control valves 33, 34, 35 and 33. The

fluid normally returns to the inlet 42 of the compressor 4I from the outlets 43, 44, 45 and 45 of the control valves 30, 35, 34 and 33. The fluid wheel cylinders and of brake 20 and 5 and 5 or brake 30 receive fluid from the control valves 33, 34, 35 and 36 when these control valves are opened.

The control valves 33, 34, 35 and 36 are alike .and the description of the one valve 33 will suiilce for all (see Figure 5). The control valve .33 has a valve body I0-I having a high pressure inlet 50, an outlet 52 leading to the braking system, and a return port 43 by which fluid may return to the compressor. The control valve 33 is sealed at one end by a cap I05 (provided with a gasket I06) screwed into the valve housing IOI. A'plug I08 provided for the opposite end has an air vent IIO provided in order to break up any vacuum which might otherwise develop between the plug I03 and a plunger 31 provided for chamber I23 formed in the valve body IIII. The plunger 31 is fitted with a rubber cup seal H2 and extends into the chamber I23. An inner plunger 3 has a plug I10 promit fluid to flow to fluid actuators 5 and 0 of brake 23 and 5 and 0 of brake 30, forcing the shoes 3 and 4 of brake 23 and 3 and 4 of brake 30 against the brake drum (not shown). If the brake 20 is operated while therotation of the brake drum (not shown) is clockwise, the shoe 3 will anchor on the fluid cylinder 5 and the shoe 4 will anchor on the fluid wheel cylinder 6. This type of brake is commonly called a twinplex' brake. when cut-01f valves of the type shown in Figures 3, 4, and 9 are placed between the control valves and the wheel cylinders. If the fluid wheel cylinder 5 or the control valve 34 should fail, the brake would still be operable by means of the control valve 33 and the fluid wheel cylinder 0. In this case both shoes 3 and 0 will anchor on the fluid wheel cylinder 5. This type of brake is commonly called a double anchor non-servo brake.

In the braking system shown in Figure 3, safety valves such as valves I03, I04, I05 and I66 may be used. These safety valves are alike and detailed description of one will sufice. The valve I03 consists of a valve body 2I5 (see Figure 4) having a chamber 2I0 and a by-pass 2I0, both running lengthwise throughout the length of the valve body 2I5. The chamber 2I6 is fitted with a piston 200 provided with a rubber seal 205 at one end, and has at the other end a recess 2H? for a. spring 204 which holds the safety'valve in released position by means of the stop ZI B against the cap 20I. Said cap 206 has an inlet port 200 and seals the valve body -2I5 by means of a gasket 202. At the extreme end opposite vided with a gasket II5 to seal a chamber I20 running along the length of the plunger I I3 and concentric to its outer diameter, and at the other end, the plunger II3 has a flange I25 extending into a compartment I21 of the valve housing "ii. The flange I25 has a recess I23 provided as a spring seat for a spring I24. Near the plugged end of the chamber I20 there is a tapered oriflce I20 and at the other end of the chamber I20 there is a small drilled hole I20 through the side wall of the inner plunger II3. From the chamber I20 01 the inner plunger II3, an outlet 3 is provided to communicate with the outlet 52 of ,the valve I0I. Two adapters H1 and I2I, provided with gaskets H0 and I22 respectively, act as spacers and furnish bearing surface for the inner plunger H3 and the outer plunger 31. 4 In operating the control valve, fluid under pressure is introduced into the chamber I21 through the inlet 50. The fluid under pressure together with the spring I24 keeps the'valve in the off position. When the outer plunger 31 is pushed inward toward the valve body IN, the port I20 0! thechamber I20 is'uncovered and allows fluid to flow into the chamber 12: and. 4

then through ports H3 and 52 respectively into the piston, in the chamber 2I0, when the valve is in'the off position, a needle valve is provided from the by-pass 2I0 to the chamber 2I6. The needle valve cooperates with a port 2II and consists of a valve stem 203 tapered at one end and threaded at the other, the tapered end fitting into the port 2 and eiIective in sealing it. A cap 201 and a gasket 200 are used to seal the valve body 2I5 at the needle valve. A port 2I2 is furnished as an outlet to the braking system. Through the wall 2I0 between the chamber 2I0 and a by-pass 2I0, a port 2 isprovided to register with a port 2I3 in the piston 200 and allows fluidto flow into the chamber 2I6 when the piston is in the released position.

In operation the port 2 is always closed by the needle valve 203 and is opened only for bleeding the system initially. Fluid under pressure flows into the safety valve through the port 200 and acts on the piston 200 and forces it further into the chamber 2I0. Normally the system beyond the piston is sealed except for the ports 2 and 2" which are in communication only when the valve is in the released position. If the system leaks beyond the safety valve, only the fluid beyond the piston 200 is lost when the brake is applied.

The hydraulic braking system shown in Figure 3 has only two control valves I50 and I5I instead of four as that shown in Figure 2. This system, however, has the four safety valves I53, I04,'I05 and I00 (valve I03 is shown in detail in Figure 4). f The control valves I50 and I5I (similar to valve 33 shown in detail in Figure 5) are operated by means of two foot pedals I52 and In the operation of the tube type brake shown from ports I55 and I of the control valves I55 and IN respectively. The safety valves I53 and I54, and, I55 and I55 are connected to wheel cylinders and 5 ot a brake I15 and with wheel cylinders 5 and 5 of a brake I15. Brakes I15 and I15 are similar to the brake shown in detail in Figure I. From the control valves I55 and I5I, fluid returns to the compressor I54 by means of outlets I55 and I52 of the control valves I55 and I5I respectively to an inlet I51 of the compressor I54.

In operation when the pedals I52 and I53 are depressed, they operate control valves I55 and I52 and allow fluid to flow to the safety valves I53 and I54, and I55 and I55 respectively. From the safety valves I53 and I54, and I55 and I55, fluid flows to the wheel cylinders 5 and 5 of brake I15, and 5 and 5 of brake I respectively. The wheel cylinders 5 and 5 of each brake force the shoes 3 and 4 against a brake drum (not shown).

In ordinary operation when the brake drum (not showniis turning in a clockwise direction and the brake H5 is applied. the brake shoe 5 anchors on the wheel cylinder 5 and the brake shoe 4 anchors on the wheel cylinder 5. This type of brake is called a twinplex brake.- If, however, part of the system should fail between the safety valve I55 and the wheel cylinder 5, the brake I15 would still be operable. Under the foregoing-conditions, the shoe 3 would anchor on the wheel cylinder 5 and the shoe 4 would also anchor on the wheel cylinder 5, regardless of the rotation of the brake drum (not shown). This type of brake is knownas a non-servo double anchor brake, and is in popular use at the present time.

The brake shown in cross-section in Figure 6 is a tube type brake and also embodies my invention. A rim 251 has a recess running around its entire periphery, said recess contains two circular rubber tubes 254 and 255, mountedone above the other. The tubes 254 and 255 have a port 255 and 252 respectively, and have relatively short segments or linings 255 mounted in the rim i immediately above.

The brake shown in cross-section in Figure -'l is a tube type brake also embodying my inven- 1 tion. Four 'circular rubber tubes 211, 215, 215

and 255 are mounted in individual recesses that run around the entire periphery of the rim 215.

Above these rubber tubes 211, 2-15, 215 and 255 are short segments of linings 215 which cover an equal portion of all four rubber tubes. Each tube 211, 215, 215 and 235 has an inlet I, 252, 253 and 254 respectively. The inlets 2 and 283 have a common source of fluid through conduit 255 and inlets 252 and 255 have a common source of fluid through conduit 255.

Figure 8 shows still another modification of a tube type brake. In this modification, there are four rubber tubes 35!, 352, 353 and 554. Each of these covers only approximately one-quarter of the entire periphery o! a rim 3. Rubber tubes "I, 352, 353 and 355 each has an inlet 351, 355, 355 and 355 respectively as an entrance for fluid. Inlets 355 and 551 are furnished fluid by a common source through a conduit 5 and inlets 355 and 355 are furnished fluid by a common source through conduit 355. Short segmentsoi brake linings 355 are set in the rim 5| I. These short segments oi-brake linings are placed immediately above one otthe rubber tubes 3", 352, 33 will.

in Figure 6, fluid under pressure enters the rubber tubes 255 and 254 by means of the inlets 252 and 2 55. The rubber t'ubes 254 and 255 therefore expand and force the relatively short lining segments 253 against the brake drum (not shown).

These modified tube type brakes (Figures 6, 7

and 8)' may be hooked up in hydraulic brake systems as shown in Figures 2 and 3, replacing the twinplex brake now shown. If one tube or group of tubes should fail the brake is still operable by means of the other tube or group of tubes.

For instance, in Figure 9 there is a diagrammatic view in which the hydraulic brake system shown in Figure 2 is used with brakes of the type shown in Figure 8. In this fig Similar parts to those shown in Figures 2 and 8 are re--' ferred to by the same numerals as are used in Figures 2 and 8.

I claim:

1. In a fluid brake system comprising a plurality of brakes, a pair of brake shoes in each brake, a plurality of fluid actuators for each brake disposed between opposite ends of the said brake shoes, a fluid pressure means connected to each of said fluid actuators, and means to isolate any of said fluid actuators from the fluid pressure means when said fluid actuators fail;

2. In a fluid brake system comprisingla plu rality of brakes each having a plurality of Individually shiitable brake shoes, a plurality of fluid actuators for each brake, a fluid pressure means connected to each of said fluid actuators,

a pressure controlling means for each of said brakes, a safety valve placed between the fluid pressure means and each of said actuators of said brakes, said safety valves isolating any of said actuators that fail. v

3. In a fluid pressure brake system comprising a plurality of brakes, a plurality of fluid actuators for each of said brakes, a separate fluid pressure means connected to each of said fluid actuators, and a pressure controlling means connected to each of said actuators of said brakes.

4. In a fluid brake, a plurality of expansible tube actuators, a fluid pressure producing means, an inlet connection from said fluid. pressure means to each of said expansible tube actuators, and means for isolating any one of said inlet connections in case of failure in pressure in the associated tube actuator.

5. A fluid brake comprising a brake drum, a plurality of expansible tube actuators, a plurality of brake lining segments, a mounting rim for said expansible tube actuators and said brake lining segments, a fluid pressure means, connections from said fluid pressure .means to an inlet for eachof said expansible tube actuators, and means for isolating any one of said inlets in case of failure of pressure in any of the associated expansible tube actuators. Y

6. For an airplane, a pair of brakes, a plurality of individually shiftable brake shoes associated with each brake, a plurality of actuators for applying each of said brakes and for serving at times as anchors for said brake shoes, a pressure means, connections from said pressure means to each of said actuators, and means for isolating any one of said actuators in case of failure of pressure therein.

7. A braking system comprising a pump, a pair of brakes, a pair of connections from said .pump, one leading toward each of said brakes,-- a pair of valves for controlling said brakes, one posi tioned in each of said connections, a pair of actubrakes respectively, and a safety valve device in each of said branch connections for isolating said branch connection and its associated actuator in case of failure of pressure in said actuator.

8. In a braking system, a drum, 8. pair of brake shoes associated with said drum each arranged to anchor independently at one end when the drum is rotating in one direction and each. arranged to anchor independently at, the other end when the drum is rotating in the other direction, a pair of cylinders, one positioned between each pair of adjacent ends of said brake shoes, means for creating hydraulic pressure, connections from said means to said pair of cylinders, and a pair f safety valves, one positioned in each of said connections so as to isolate each of said connections in case of failure of pressure in the associated wheel cylinder.

9. In a hydraulic braking system comprising a drum, a plurality of brake shoe segments positioned in said drum, a plurality of flexible tubes associated with said brake shoe segments for moving said segments into contact with said drum to accomplish braking, a plurality of connectlons, each one connected to one of said tubes, means for isolating each of said connections from the other in case of failure of pressure in the associated tube, and means for creating pressur associated with said connections.

10. In a braking system, a drum, a pair of brake shoes associated with said, drum each arranged to anchor independently at one end when the drum is rotating in one direction and each arranged to anchor independently at the other end when the drum is rotating in the other direction; a pair of wheel cylinders, one positioned between each pair of adjacent ends of said brake shoes, means for creating hydraulic pressure comprising a pump and a valve for controlling the pressure supplied by said pump and mstributing it to said wheel cylinders, connections from said means to said pair of cylinders, and a pair of safety valves positioned in said connections so as to isolate each of said connections in case of failure of pressure in the associated wheel cylinder;

11. In a hydraulic braking system comprising a drum, a plurality of brake shoe segments positioned in said drum, a plurality of flexible tubes associated with said brake shoe segments for moving said segments into contact with said drum to accomplish braking, a plurality of connections, each one connected to one of said tubes, means for isolating each of said connections from the other in case of failure of pressure in the associated tube. and means for creating pressure in said connections comprising a pump and awake for controlling-said pressure and distributing it to said tube connections for applying said brakes.

12. In a hydraulic braking system comprising a drum, a plurality of brake shoe segments positioned in said drum, a pair of flexible tubes arranged in parallel relationship and associated with said brake shoe segments for moving said segments into contact with said drum to accomplish braking, a plurality of connections, each one connected to one of said tubes, means for isolating each of said connections from the other in case of failure of pressure in the associated tube, and means for creating pressure associated with said connections, whereby said tubes cooperate normally to actuate said shoes, and whereby each of said tubes in case of failure of the other actuates said shoes independently.

13. In a hydraulic braking system comprising a drum, a plurality of brake shoe segments positioned in said drum, a plurality of flexibletubes each comprising a segment of a circle associated with said brake shoe segments for moving said segments into contact'with said drum to accomplish. braking, a plurality of connections, each one connected to one of said "tubes, means for isolating each of saidconnections from the other in case of failure of pressure in the associated tube, and means for creating pressure associated with said connections.

HENRY-H. KERR.

CERTIFICATE OF CORRECTION. I Patent No. 2,215, 682. I Ju1 1e 17, 1914.1.

' HENRY 121-. KERR.

It 15 hereby certified that error appears in the. printed specificationof the abo ve numbered patent requiring correction a'sfollo'ws; Page 2, second col umn, line 7, 'efter the word "fluid" insert --wheel-' page 5 mond celumh,-1ine 68, claim 6, 'strike out "a" before --pres sure-- and that rthe said Letters Patent sholild be reed with this cbrreet'iqn therein thet" the same may conform to the record of the casein the Batent Office. Signed and mm this 28th day of April, A. 1). 195,2.

Henry Ven'. Arsda1e,' Acting bom is sionerjofr Patents.

(seai) 

